11th ICRS Abstract book - Nova Southeastern University

Poster Mini-Symposium 11: From Molecules to Moonbeams: How is reproductive timing regulated in coral reef organisms?
11.411
Pseudo-4d Visualization Of The Seahorse Larva Head During Ontogenesis
Tim MIGAWSKI* 1 , Martin HEß 2
1 Center for Tropical Marine Ecology, Bremen, Germany, 2 BioZentrum der LMU
München, Planegg, Germany
The developing seahorse larva undergoes a metamorphosis from hatching to the final
seahorse morphology. At the beginning the seahorse larvae look like “normal” teleost
larvae, with a voluminous yolk sack and an elongated body. During the development in
the male brood pouch a metamorphosis towards an erected, fully differentiated juvenile
seahorse takes place within ± two weeks.
In this study larval stages, from hatching to the differentiated juveniles, were collected
from a male of Hippocampus cf. reidi. Information on the formation of the eyes, the
snout and the development of internal organ systems is given, as a first demonstration of
the changing seahorse head with all internal organ systems.
After fixation section series were cut through the heads of the larval stages beginning
with the snout tip. Digital images of each mechanical slice were made on a light
microscope, imported into 3D-rendering software (Amira TM ), converted to stacks, aligned
and segmented manually. The abstracted organ contours were used to compute surfacemodels
of several organ systems, to be displayed at any angle of view and for some
morphometric analysis. The virtual 3D-models show the internal organs like brain,
olfactory epithelia, jaw- and eye-muscles, cartilages and bones, lateral line system and
labyrinth organ in different colours. Thus it was possible to display single or several
organ systems of the seahorse larva head in any combination, transparency and angle of
view at different developmental stages – sort of handling a virtual “transparent fish” in
space and time. The method presented here gives detailed insight in the morphogenesis of
the seahorse head during metamorphosis, e.g. the effects of eye formation and snout
development to all neighbouring tissue structures involved. In further experiments
biochemical effects in different live stages of seahorses will be tested in view of active
bio compounds and their influence on specific cell types.
11.412
Spawning Induction Method Responses Of Trochidae Gastropods in Closed System
Aquaculture
Brian PLANKIS* 1
1 Aquaculture Research, The DIBS Foundation, Manvel, TX
The marine ornamentals trade is almost exclusively dependent on wild collection of
herbivores to meet commercial demand. Collection of gastropods alone is in excess of
500,000 individuals per year and could be considerably higher due to lack of reporting
requirements. Removal of grazers could have a negative impact on reef resilience and
developing captive breeding programs to supplant wild collection should help preserve
diversity and herbivore abundance in collection locales.
The Desirable Invertebrates Breeding Society Foundation (DIBS Foundation) is a nonprofit
organization dedicated to testing methods of closed system aquaculture on marine
invertebrates. The families Turbinidae and Trochidae contains many herbivores that are
collected or are excellent substitutes for current gastropods used in the marine
ornamentals trade. While flow through aquaculture systems using natural sea water have
been studied for several members of the families, most notably Trochus niloticus and
Turbo marmoratus, reports are rare for closed system aquaculture utilizing artificial sea
water with multiple spawning attempts per individual.
The DIBS Foundation is conducting spawning induction trials on members of the
Trochidae family that have not been previously reported in the literature. This
presentation will report spawning induction methods utilized by The DIBS Foundation in
closed system aquaculture utilizing aged artificial sea water and individuals subjected to
multiple spawning inductions over a 12 month period. I will discuss the methods utilized,
the response of three Trochidae members (Trochus stellatus, Trochus sp., and Tegula sp.)
to the methods, and initial results of fertilizing the resulting gametes. Discussion will
focus on the varied responses by the different species, the need for further study of
broodstock conditioning and recovery intervals and implications for the potential of
utilizing captive populations for a regular supply to the marine ornamentals trade to
reduce the need for wild collection.
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